Field of the Invention
The invention relates to a semiconductor device and a method of fabricating the same.
Description of Related Art
With the integration of semiconductor devices, in order to achieve high density and high performance, fabrication of semiconductor devices has evolved into stacking upward in the vertical direction, such that the wafer area can be used more efficiently. Therefore, semiconductor structures or openings having a high aspect ratio are common in small-sized devices.
When fabricating the aforementioned devices, the patterning process is usually carried out with very high etching selectivity in order to form trenches having a high aspect ratio. However, in the case of using very high etching selectivity, the problem of residual material layer on the sidewall of the trench may occur. If there is residual material layer on the sidewall of the trench and the residual material layer is conductive, improper conduction may occur between the semiconductor devices and impair the electrical performance of the devices. In view of the above, how to pattern the material layer (conductive layer) in the semiconductor structure with the trench having a high aspect ratio without leaving residual material layer on the sidewall of the trench is an issue that needs to be addressed.